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Which apps can measure a room with an iPhone?

There are four kinds: Apple's built-in Measure app, LiDAR scanners, camera-based apps without LiDAR, and drawing apps where you type in the measurements yourself. Here is the difference, and what each type can and cannot do.

The four kinds of apps for measuring a room

When people ask which apps can measure a room with an iPhone, they usually lump together four different things. Each of the four types solves a different problem, and the right choice depends entirely on what you need the measurements for: a single measurement for a bookcase, an area for a painter's quote, or a full floor plan for a property sale.

1. Apple's Measure app — single measurements, free, already installed

Measure ships with iOS and sits on every iPhone from the iPhone SE (2nd generation) onwards. You point the phone at a spot, set a start point, move the phone to the end point, and get the distance. The app also includes a spirit level. On iPhone models with LiDAR, it can additionally measure a person's height, and it more easily recognises a rectangle — a table, a window, a picture on the wall — and gives both width and height at once.

Measure is excellent for one measurement at a time: will the sofa fit through the door, how high is the ceiling, how wide is the window opening. But it does not tie the measurements together into anything. No floor plan comes out, no square metres, no file you can pass on. It is a digital tape measure, not a drawing board.

2. LiDAR scanners — the whole room at once

LiDAR scanners use the small rangefinder that sits next to the camera lenses on the iPhone Pro models. You walk around the room with the phone, and the app builds up the geometry as you go: walls, doors, windows, openings, and often furniture too. What comes out is a floor plan, an area, and usually a 3D model as well.

Most apps of this kind for iPhone are built on RoomPlan, Apple's own developer framework from 2022. It is not an app you can download — it is the engine underneath many of them. That also explains why a lot of LiDAR scanners feel similar to use: the same engine is looking at the room.

The category ranges from broad construction-industry tools to apps built for one specific job. HouseSense belongs to the latter: it is built for homes, and works out areas, takeoffs and sunlight from the scan. Apps come and go in the App Store, so always check that the one you download is still being updated, and what it can export.

The requirement: LiDAR is only in the iPhone 12 Pro and newer Pro models, plus every iPad Pro from 2020 onwards. An iPhone 15 Plus does not have it; an iPhone 15 Pro does. If your phone lacks LiDAR, the app can still be downloaded, but the scan button will either be missing or fall back to the camera alone.

3. Camera-based AR apps — without LiDAR

Some apps measure without LiDAR by tracking how the image shifts as you move the phone — the same technique Apple's Measure app uses on non-Pro models. It works, but it is noticeably more sensitive: a plain white wall without texture, poor light, a shiny tile or a mirror gives it fewer points to hold on to, and the measurements can drift.

This category is good for quick estimates and for rooms with patterns and edges to latch onto. If the numbers are going into a contractor's quote, verify at least one measurement per room with a tape measure.

4. Drawing apps — you type in the measurements yourself

The fourth type does not measure anything at all. You draw the room's shape on the screen and type in the measurements — either from a tape measure or a laser distance meter. In return, the numbers are exactly as accurate as your own measuring is, and it works on any iPhone regardless of age, in the dark, in an empty house with no power, and in a room full of moving boxes where no scanner could ever see the walls.

Here is how it works in HouseSense: you drag a rectangle onto graph paper, and that is a room. Measurements are typed in as whole centimetres and as internal measurements — wall to wall, the way you would measure it yourself. Walls snap to their neighbour and become one shared wall, so two rooms never count the same square metres twice.

Bonus: companion apps for a laser distance meter

If you own a Bluetooth laser distance meter — from Leica or Bosch, for example — the manufacturer usually has a companion app that receives the measurements directly from the meter and places them into a simple sketch. This is the most accurate of all the options for a single measurement, because the laser measures against a physical wall and never has to guess where the wall is.

What do the different apps give you?

• A single measurement: all four types can do this. Apple's Measure app is free and fastest.
• Square metres: LiDAR scanners and drawing apps. Measure cannot do this.
• A floor plan with measurements: LiDAR scanners and drawing apps.
• A 3D model: mainly LiDAR scanners.
• A file for a contractor or architect: look for PDF for printing, and DXF or OBJ/USDZ to open in drawing software. HouseSense writes DXF, OBJ, USDZ and PDF, among others.

How accurate does it get?

No app can guarantee accuracy to the centimetre, because it depends on the room and on how you walk. It is worth knowing what moves the number:

• Drift: the further you walk, the more the phone's sense of its own position can slip. Large, long rooms are harder than small ones.
• Glass and mirrors: both LiDAR and camera get confused by them. A mirror can look like a hole in the wall.
• Soft and movable surfaces: curtains, rugs hung on a wall, moving boxes stacked against the wall — the scanner measures what it sees, not the wall behind it.
• Skirting boards and protrusions: a scanner can place the wall line at the skirting rather than at the plaster.
• Sloped ceilings and attic rooms: here there is rarely one single correct square-metre figure. Habitable floor area and gross floor area are two different numbers under a sloped ceiling.

Work out what an error actually means. A room you have measured at 4.00 × 3.00 m is 12.00 m². If the scan is 2 cm too generous on both sides, you get 4.02 × 3.02 = 12.14 m² — 0.14 m² too much, roughly 1.2 %. For paint and flooring it makes no difference; you budget 5–10 % waste on top anyway. For a construction case or a dispute over a home's floor area it is not irrelevant, and the measurements need to be verified with a tape measure.

Should the app cost anything?

Apple's Measure app comes with the phone. Floor-plan apps are usually free to try, and payment only kicks in when you want to export or save more than one project. Look for one thing above all: can you get your own data back out again? A floor plan you cannot export is hard to use for anything.

How to choose

1. What are the measurements for? A single measurement → Apple's Measure app. An area or a drawing → a purpose-built app.
2. Does the phone have LiDAR? No → pick an app that can also be drawn in, rather than one that can only scan.
3. Will anyone else use the drawing? Then check the export formats before you start: PDF for printing, DXF for drawing software, USDZ or OBJ for 3D.
4. Where does your data live? Some apps send the scan to a server. HouseSense stores everything in your own iCloud, with no account and no server.
5. Can you correct it afterwards? No scan turns out perfect on the first try. An app where you can move a wall and type in the right measurement is worth more than one that can only scan again.

One thing no app can do

No app on an iPhone can determine whether a wall is load-bearing. A scanner measures where the wall stands and how thick it looks — not what it is holding up. That question needs a building surveyor or an engineer on site, and you should never take that answer from an app.